Antenna Structure With Reconfigurable Pattern And Manufacturing Method Thereof

ABSTRACT

The invention provides an antenna structure with reconfigurable pattern, which comprises a grounded plane, at least an active antenna electrically connected to an RF signal source, at least a current dragger electrically connected to the grounded plane, and a controller. The at least an active antenna and the at least a current dragger are distributed on or near the grounded plane. The controller disables or enables the at least a current dragger at an operating frequency band to switch the RF current applied to the grounded plane to flow into or against the at least a current dragger, thereby a plurality of radiation patterns may be configured.

TECHNICAL FIELD

The present invention generally relates to an antenna structure withreconfigurable pattern and the manufacturing method thereof.

BACKGROUND

The smart antenna is an important part of antenna design for thewireless communication system, mainly including multiple input multipleoutput (MIMO) antenna technology and adaptive antenna system (AAS). MIMOantenna technology uses multiple wireless transmission paths to increasethe signal coverage area or the amount of transmission data.

AAS technology uses multiple antennas to form an antenna array,dynamically adjusts the input power for each antenna unit for beamsteering towards the target devices for data transmission, and achieveshigh efficient transmission by increasing signal to noise ratio (SNR)and reducing same frequency interference. In the mean time, if a dynamicobject, such as human or other obstacles, blocks the signal transmissionpath to interfere, the system will readjust the beam steering in realtime to form new transmission path and continue the transmission.

The antenna array has a high directivity (or the narrow main beambeamwidth) configuration precision. As shown in FIG. 1, the way toadjust the directivity of antenna array 100 requires a plurality ofphase adjusters 110, power adjusters 120, a power divider 130, and adigital signal processor (DSP) 140. By configuring the phase andamplitude of the input signal to each antenna to achieve the effect ofbeam direction switch, the overall volume and the cost of smart antennaare also increased.

The configuration of antenna radiation pattern may be realized in manyways, such as, array antenna (multiple antennas), changing theelectromagnetic coupling, changing the RF current distribution, and soon. The array antenna approach is to control the excited phase andamplitude of each antenna to composite a specific radiation pattern. Thechanging electromagnetic coupling approach, such as Yagi antenna,configures passive antenna to wave-guided or reflective structure tochange the beam direction. The exemplary Yagi antenna structures aredisclosed in U.S. Pat. No. 7,268,738, No. 7,193,574, No. 7,180,465, No.6,753,826, and No. 6,211,830.

Take Yagi antenna structure 220 of FIG. 2A as an example. Yagi antenna200 includes a reflective back plane 202, two passive antennas 203 (leftand right), and an active antenna 201. Passive antennas may change theresonance length by connecting capacitive or inductive load to determinewhether the effect is a wave-guided or reflective structure. FIG.2B-FIG. 2D use the yz-cross-section of Yagi antenna structure 200 todescribe the theory of the wave-guided or reflective structure.

For example, in FIG. 2B, the left passive antenna may be connected to aninductive load to increase the resonance length to become reflectivestructure 203 a, where reflector 203 a is longer indicating left passiveantenna connected to inductive load to increase the resonance length. InFIG. 2C, the right passive antenna may be connected to capacitive loadto shorten the resonance length to become director 203 b, where director203 b is shorter indicating right passive antenna connected tocapacitive load to shorten the resonance length. In FIG. 2D, reflector203 a and director 203 b make the main beam direction of active antenna201 leaning to the right.

Reflective back plane 202 is to make the beam radiate in thex-direction. The Yagi antenna structure theory may increase the antennadirectivity, which is not related to the pattern configuration. Thistype of antenna has a configuration structure with maximum beam steeringangle 180°, and the active antenna must have the same polarization asthe passive antenna. In other words, the wave-guided or reflectivestructure must be parallel with the active antenna.

FIGS. 3A-3C show three similar antenna structures with correspondingradiation patterns. As shown in FIGS. 3A-3C, the antenna on threeantenna structures 311-313 with different RF currents will generatedifferent radiation patterns 321-323. In FIG. 3A, balanced antenna 311has a symmetrical structure so that the RF current displays symmetricaldistribution; therefore, radiation pattern 321 is also symmetrical. InFIG. 3B, unbalanced antenna structure 312 having the system groundedplane as part of the antenna radiation metal. Because the structure isasymmetrical, the asymmetrical RF current distribution makes the beamdirection leaning towards the system grounded plane.

The unbalanced antenna structure and system grounded plane havedifferent relative position, the RF current distribution will also bedifferent, as shown in FIGS. 3B-3C, therefore, will have differentradiation patterns 322, 323 and optimal signal reception direction willalso be different.

The changing RF current approach to realize the antenna radiationpattern is disclosed in U.S. Pat. No. 6,456,248, No. 7,084,816, No.6,771,223, No. 6,441,787, No. 7,202,823.

Take the antenna device disclosed by U.S. Pat. No. 7,084,816 of FIG. 4as an exemplar. Antenna device 400 includes a grounded conductor 410,auxiliary ground conductors 420 a, 420 b, an antenna element 430, andchanging elements 440 a, 440 b. Antenna element 430 is placed on top ofgrounded conductor 410 through an insulator. Auxiliary ground conductors420 a, 420 b are separate from first ground conductor 410. Changingelements 440 a, 440 b change the direction of antenna element 420through the configuration between grounded conductor 410 and auxiliarygrounded conductor 420 a, and through the configuration between groundedconductor 410 and auxiliary grounded conductor 420 b, respectively. Theauxiliary grounded conductors 420 a, 420 b are only for the extension ofthe ground plane, which do not affect the resonance frequency of antennaelement 430 and need not resonate with the operating frequency ofantenna element 430. Besides, antenna device 400 is a patch typeantenna.

FIG. 5 shows a portable wireless communication device disclosed by U.S.Pat. No. 6,456,248. In wireless communication device 500, under thefirst and the second radio frequencies, the input impedance at open endsof conductor planar plate 511 is approaching infinity. The function isto prevent RF current from flowing into conductor planar plate 511 andshield case 502 so that the wireless communication system, under any RF,may reduce the average of specific absorption rate (SAR) ofelectromagnetic wave energy per unit mass.

SUMMARY

The disclosed embodiments may provide an antenna structure withreconfigurable pattern and manufacturing method thereof.

In an exemplary embodiment, the disclosed relates to an antennastructure with reconfigurable pattern, comprising a grounded plane, atleast an active antenna electrically connected to an RF signal source,at least a current dragger electrically connected to the grounded plane,and a controller. The at least an active antenna and the at least acurrent dragger are distributed on or near the grounded plane. Thecontroller disables or enables the at least a current dragger at anoperating frequency band to switch the RF current applied to thegrounded plane to flow into or against the at least a current dragger,thereby a plurality of radiation patterns are configured.

In another exemplary disclosed embodiment, the disclosed relates to amanufacturing method for an antenna structure with reconfigurableradiation patterns. The method comprising: distributing or placing atleast an active antenna near a grounded plane and electricallyconnecting to an RF signal; electrically connecting at least a currentdragger to the grounded plane and regulating the guide-in/cut-off modeof current dragger within an antenna operating frequency band andcorresponding current path; ensuring each current dragger underguide-in/cut-off mode effectively guiding in or cutting off the RFcurrent on the grounded plane to the current dragger; distributing orplacing the current draggers near the grounded plane; and within theantenna operating frequency band, by enabling or disabling the currentdragger, reconfiguring the RF current guide-in/cut-off on the groundedplane to the current dragger.

The foregoing and other features, aspects and advantages of the presentinvention will become better understood from a careful reading of adetailed description provided herein below with appropriate reference tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary schematic view of an array antenna structure.

FIG. 2A shows an exemplary schematic view of a Yagi antenna structure.

FIGS. 2B-2D show an exemplary schematic view of the theory of wave-guideor reflective structure of FIG. 2A.

FIGS. 3A-3C show three similar types of antenna structures andcorresponding radiation patterns.

FIG. 4 shows an exemplary schematic view of an antenna device.

FIG. 5 shows an exemplary schematic view of an antenna device and aportable wireless communication device.

FIG. 6 shows an exemplary schematic view of antenna structure withreconfigurable radiation patterns, consistent with certain disclosedembodiments.

FIGS. 7A-7B show exemplary schematic views of antenna radiation patternchange through configuring modes of antenna structure, consistent withcertain disclosed embodiments.

FIGS. 8A-8C show exemplary schematic views of three embodiments ofpseudo antenna type current dragger, consistent with certain disclosedembodiments.

FIGS. 9A-9C show schematic views of three exemplary resonator typecurrent draggers, consistent with certain disclosed embodiments.

FIG. 10 shows an exemplary schematic view of the multi-port resonator ofFIGS. 9A-9C, consistent with certain disclosed embodiments.

FIG. 11A shows a schematic view of an exemplary monopole type currentdragger, consistent with certain disclosed embodiments.

FIG. 11B shows an exemplary schematic view of an antenna structure witha monopole type current dragger of FIG. 11A, consistent with certaindisclosed embodiments.

FIGS. 12A-12B show the antenna radiation patterns corresponding to thegrounded plane current distribution of antenna structure of FIG. 11 incut-off/guide-in modes, respectively, consistent with certain disclosedembodiments.

FIG. 13 shows an exemplary schematic view of a working example of anantenna with reconfigurable radiation pattern, consistent with certaindisclosed embodiments.

FIG. 14A shows an enlarged view of a pseudo antenna type current draggerof FIG. 8A, consistent with certain disclosed embodiments.

FIG. 14B shows an exemplary schematic view of an antenna structure,where a region in the antenna structure having an active antenna and twopseudo type antenna current draggers of FIG. 8A, consistent with certaindisclosed embodiments.

FIG. 14C shows an enlarged view of the region of FIG. 14B, consistentwith certain disclosed embodiments.

FIGS. 15A-15B show an exemplary antenna radiation pattern correspondingto a current dragger in cut-off mode and a current dragger in guide-inmode as in FIG. 14C, consistent with certain disclosed embodiments.

FIGS. 16A-16B show an exemplary antenna radiation pattern correspondingto two current draggers of FIG. 14C in guide-in mode, consistent withcertain disclosed embodiments.

FIGS. 17A-17B show an exemplary antenna radiation pattern correspondingto two current draggers of FIG. 14C in cut-off mode, consistent withcertain disclosed embodiments.

FIG. 18 shows an exemplary schematic view of the comparison of antennaradiation patterns of FIGS. 15-17, consistent with certain disclosedembodiments.

FIG. 19 shows an exemplary schematic view of a pair of antennastructures with reconfigurable radiation pattern having six types ofradiation patterns, consistent with certain disclosed embodiments.

FIG. 20A shows an exemplary enlarged view of resonator type currentdragger of FIG. 9B, consistent with certain disclosed embodiments.

FIG. 20B shows an exemplary schematic view of an antenna structurehaving a resonator type current dragger of FIG. 20A, consistent withcertain disclosed embodiments.

FIG. 21A shows an exemplary schematic view of the antenna structure ofFIG. 20B cutting off RF current from the resonator type current draggerwhen the resonator type current dragger is configured to the cut-offmode, consistent with certain disclosed embodiments.

FIG. 21B shows an exemplary schematic view of the antenna radiationpattern corresponding to the scenario of FIG. 21A, consistent withcertain disclosed embodiments.

FIG. 22A an exemplary schematic view of the antenna structure of FIG.20B guiding in RF current to the resonator type current dragger when theresonator type current dragger is configured to the guide-in mode,consistent with certain disclosed embodiments.

FIG. 22B shows an exemplary schematic view of the antenna radiationpattern corresponding to the scenario of FIG. 22A, consistent withcertain disclosed embodiments.

FIG. 23 shows an exemplary flowchart of the method for manufacturing theantenna structure with reconfigurable radiation patterns, consistentwith certain disclosed embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The disclosed exemplary embodiment of the present invention may providean antenna structure with reconfigurable patterns. The antenna structureviews an antenna grounded plane as a part of the antenna radiating body.At least a current dragger, through a controller to control a switchingelement embedded in the current dragger, guides in or cuts off the RFcurrent on the grounded plane to the current dragger to control the RFcurrent distribution on the antenna grounded plane, thereby forming aplurality of antenna radiation patterns.

The exemplary embodiment of FIG. 6 discloses an antenna structure withreconfigurable pattern, consistent with certain disclosed embodiments.Referring to FIG. 6, antenna structure 600 comprises a grounded plane610, N active antennas 631-63N, M current draggers 641-64M, and acontroller 620, where N and M are both positive integers. Activeantennas 631-63N are electrically connected to an RF signal. Currentdraggers 641-64M are electrically connected to grounded plane 610.Active antennas 631-63N and current draggers 641-64M are distributed onor near grounded plane 610. When within antenna operating frequencyband, controller 620 enables or disables current draggers 641-64M toconfigure the RF current of grounded plane 610 to guide in or cut off tocurrent dragger 641-64M to form a plurality of radiation patterns.

For example, in FIG. 6, controller 620 may be connected to currentdraggers 641-64M, and each of current dragger 641-64M may have at leasta switch or an adjustable load. When a switch or an adjustable load ofcurrent dragger 641-64M is configured to the guide-in mode, the RFcurrent on the grounded plane is guided into the current draggercorresponding to the switch or the adjustable load. On the other hand,if the switch or the adjustable load is configured to the cut-off mode,the input impedance of the current dragger towards RF current may beviewed as open, and the RF current on the grounded plane is cut off fromthe corresponding current dragger.

The guide-in mode and the cut-off mode may be regulated by controller620 to control current dragger to whether to resonate in the operatingfrequency band. For example, when the switch or the adjustable load of acurrent dragger is configured to the guide-in mode, the current draggerresonates within the operating frequency band and shows low inputimpedance towards the RF current. Therefore, the RF current may beguided into the current dragger. When the current dragger is configuredto the cut-off mode, within the operating frequency band, the currentdragger shows high input impedance to the RF current, i.e., the RFcurrent is cut off from the current dragger.

FIGS. 7A-7B show exemplary schematic views of antenna radiation patternchange through configuring modes of antenna structure, consistent withcertain disclosed embodiments. As shown in FIG. 7A, when the antennastructure is in the antenna operating frequency band and current dragger741 is disabled, i.e., cut-off mode, current dragger's input impedanceto RF current may be viewed as open, where the arrow of grounded planeis the direction of the RF current, and mark 710 a is the main beamdirection of antenna radiation pattern 710. As shown in FIG. 7B, whenthe antenna structure is in the antenna operating frequency band andcurrent dragger 741 is enabled, i.e., guide-in mode, RF current isguided into current dragger 741 so that the main beam direction ofantenna radiation pattern 720 is roughly reconfigured from toward downto toward right, marked as 720 a.

After a current dragger is added to an active antenna, the radiationpattern is the linear superposition of the radiation patterns formed bythe RF current distributions of the two active antennas (i.e., one isthe active antenna, and the other one is the active antenna replacingthe current dragger), where relative phase and amplitude of the currentdragger to the active antenna RF current is a factor of the linearcoefficient of the radiation pattern formed by the RF currentdistribution of the other active antenna.

Therefore, the disclosed embodiments may affect the RF current on thegrounded plane through reconfiguring each current dragger to guide in orcut off the RF current. Different configuration combinations allow theantenna structure to form different RF current distributions. The changeof RF current distribution on the grounded plane will affect the farfield pattern (directivity) and the near field electromagnetic energydistribution of the antenna, such as specific absorption rate (SAR) ofelectromagnetic energy per mass unit. Therefore, the antenna structurewill have the reconfigurable patterns.

In comparison with the technique of prior arts to change antennaradiation pattern by electromagnetic coupling, the disclosed exemplaryembodiments does not impose any restriction on the polarization anddistance between the active antenna and the passive antenna. Hence, thedisclosed exemplary embodiments may be applicable to the low profileantenna structure.

The current dragger may be realized by, for example, pseudo antennatype, resonator type, or monopole type. FIGS. 8A-8C show three exemplarsof pseudo antenna type current dragger, consistent with certaindisclosed embodiments, where the switch element of the current draggercan be, for example, a switch or an adjustable load. The followingexamples use a switch for description.

In FIG. 8A, switch 810 of pseudo antenna type current dragger is locatedbetween pseudo antenna 811 and an extension 812 of pseudo antenna 811.In FIG. 8B, switch 820 of pseudo antenna type current dragger is locatedbetween pseudo antenna 821 and grounded plane 822. In FIG. 8C, switch830 of pseudo antenna type current dragger is located inside pseudoantenna 831; in other words, switch 830 is located between two segmentsof pseudo antennas 831 a, 831 b. The aforementioned pseudo antenna maybe a conductor, such as metal plate. RF current may be coupled ordirectly flow into the pseudo antenna.

FIG. 9A and FIG. 9C are two exemplary schematic views of resonance typecurrent draggers, consistent with certain disclosed embodiments. In FIG.9A, resonance type current dragger is realized with a multi-portresonator 911. In FIG. 9B and FIG. 9C, the switch element of theresonance type current dragger may be a switch or an adjustable load.The following uses switch for explanation. In FIG. 9B, switch 920 ofresonance type current dragger is designed to be located inside amulti-port resonator 921. In other words, switch 920 is placed betweentwo resonator segments 921 a, 92 b. In FIG. 9C, switch 930 of resonancetype current dragger is designed to be located between multi-portresonator 931 and an extended load 932 of multi-port resonator 931.Multi-port resonator 931 is connected to extended load 932 throughswitch 930, and may switch the resonance frequency.

As shown in FIG. 10, the connection structure of the output terminal ofthe aforementioned multi-port resonator may be open 1034, shorted(grounded) 1033, or connected to a switch element, such as switch 1032,and then grounded, or connected to another resonator 1031, or connectedto a switch element, such as switch 1035, and then connected to anotherload 1036.

FIG. 11A shows a schematic view of a monopole type current draggeraccording to the present invention. As shown in FIG. 11A, the switchelement of monopole type current dragger 1100, such as switch 1110, islocated between two segments of L-arm 1111. L-arm 1111 has onetermination grounded 1199. FIG. 11B shows an exemplary schematic view ofan antenna with monopole type current dragger 1100, consistent withcertain disclosed embodiments, where antenna structure 1120 includesactive antenna 1121 and monopole type current dragger 1100, both placedon the outside of grounded plane 1122.

FIG. 12A and FIG. 12B show the antenna radiation patterns correspondingto the grounded plane current distributions of aforementioned antennastructure 1120 in cut-off and guide-in modes respectively, consistentwith certain disclosed embodiments. In FIG. 12A, antenna structure 1120is in the cut-off mode and the main beam direction of antenna radiationpattern faces the 45° direction. In FIG. 12B, antenna structure 1120 isin the guide-in mode. Because the current dragger's guiding in the RFcurrent has increased another current direction on the grounded plane,the main beam of the antenna radiation pattern faces the −155°direction. In other words, the exemplary antenna structure may beconfigured to have main beam facing 45° direction or −155° direction.

FIG. 13 shows an exemplary schematic view of a working example of theantenna with configurable radiation patterns, consistent with certaindisclosed embodiments. As shown in FIG. 13, active antenna 1311 andcurrent draggers 1321-1323 can be placed on a grounded plane 1310, andactive antenna 1312 and current dragger 1324 can be placed outside ofgrounded plane 1310. In other words, current draggers are neitherlimited to be co-planar with the active antenna, nor limited to beco-planar with the grounded plane.

The following uses the pseudo type current dragger of FIG. 8A as anexample to describe the antenna radiation patterns corresponding to thetwo pseudo antenna type current draggers in an antenna structure indifferent configurations. FIG. 14A-FIG. 14C show respectively the pseudoantenna type current dragger, the antenna structure and the two pseudoantenna type current draggers of the antenna structure.

FIG. 14A shows an exemplary view of an actual structure of the pseudotype current dragger of FIG. 8A, consistent with certain disclosedembodiments. As shown in FIG. 14A, pseudo antenna type current dragger1400 comprises an extended part 1412, pseudo antenna 1411, and switch1410 located between the above two. Mark 1422 is the grounded plane ofthe antenna structure.

FIG. 14B shows an exemplary schematic view of an antenna structure witha plurality of current draggers, consistent with certain disclosedembodiments. As shown in FIG. 14B, region 1430 of antenna structure 1420has an active ante and two pseudo antenna type current draggers 1400located outside of grounded plane 1422. In the embodiment, the size ofgrounded plane 1422 is 260 mm*180 mm. FIG. 14C shows an enlarged view ofregion 1430, where mark 1431 is active antenna and two pseudo antennatype current draggers are marked as 1421 a, 1421 b. The followingdescribes antenna radiation patterns corresponding to two pseudo antennatype current draggers 1421 a, 1421 b in different configuration modes.

In FIG. 15A, pseudo antenna type current dragger 1421 a is in guide-inmode. In other words, switch 1510 a is in OFF state; therefore, theguided-in RF current flows in the direction of arrow. Pseudo antennatype current dragger 1421 b is in cut-off mode. In other words, switch1510 b is in ON state; therefore, the RF current is cut off andvirtually no RF current is present. With pseudo antenna type currentdragger 1421 a in guide-in mode and pseudo antenna type current dragger1421 b in cut-off mode, FIG. 15B shows the antenna radiation patterncorresponding to the current distribution on grounded plane 1422 ofantenna structure 1420. The main beams of antenna radiation pattern facethe −135° and 55° directions, respectively, as the arrows indicate.

In FIG. 16A, pseudo antenna type current draggers 1421 a, 1421 b areboth in guide-in mode. In other words, switches 1510 a, 1510 b are bothin OFF state; therefore, the guided-in RF current flows in the directionof arrow. With pseudo antenna type current draggers 1421 a, 1421 b bothin guide-in mode, FIG. 16B shows the antenna radiation patterncorresponding to the current distribution on grounded plane 1422 ofantenna structure 1420. The main beams of antenna radiation pattern facethe −135° direction, as the arrow indicates.

In FIG. 17A, pseudo antenna type current draggers 1421 a, 1421 b areboth in cut-off mode. In other words, switches 1510 a, 1510 b both arein ON state; therefore, the RF current is cut off and virtually no RFcurrent is present. With pseudo antenna type current draggers 1421 a,1421 b both in cut-off mode, FIG. 17B shows the antenna radiationpattern corresponding to the current distribution on grounded plane 1422of antenna structure 1420. The main beams of antenna radiation patternface the 55° direction, as the arrow indicates.

In the exemplary embodiments of FIG. 15-FIG. 17, the main beam ofantenna ration patterns can be configured to face 55°, −135° and 55°,−135° dual-beam. FIG. 18 shows the comparison of antenna radiationpatterns of FIG. 16, FIG. 17. It is observed that the reconfigurationcovers the range of nearly 180°, where the antenna gain of beamdirection (about) −135° of FIG. 16B is about 6.95 dBi more than that ofFIG. 17B, while, vice versa, the antenna gain of beam direction (about55°) of FIG. 17B is about 6.95 dBi more than that of FIG. 16B.

FIG. 19 shows that a pair of antenna structure with reconfigurableradiation patterns may display six different radiation patterns,consistent with certain disclosed embodiments. In the exemplaryembodiment, the size of grounded plane is 220 mm*180 mm.

The disclosed exemplary embodiments also simulate the location change ofcurrent dragger to observe the change of antenna radiation pattern andcurrent distribution. The simulation result shows that the locationchange of current dragger will lead to different RF current distributionon grounded plane; thus, the radiation pattern will be different. Thesimulation may be used as reference when determining the location ofcurrent dragger.

The following uses resonator type current dragger of FIG. 9B as anexample to describe the antenna radiation patterns corresponding to theresonator type current dragger in an antenna structure in differentconfiguration modes.

FIG. 20A shows a cross-sectional view of the resonator type currentdragger of FIG. 9B, consistent with certain disclosed embodiments. Asshown in FIG. 20A, resonator type current dragger 2000 is a multi-portresonator with inductor 2011 and capacitor 2012, and switch 2030 isdesigned to be located inside the multiport-resonator. The outputtermination of the multi-port resonator is connected to a switch element2040 and then grounded 2050.

FIG. 20B shows an exemplary schematic view of an antenna structure witha resonator type current dragger 2000, consistent with certain disclosedembodiments, where antenna structure 2020 has a grounded plane 2021, andan active antenna 2022 and a resonator type current dragger 2000 locatedoutside of grounded plane 2021. In the exemplary embodiment, the size ofgrounded plane 2021 is 260 mm*180 mm.

When resonator type current dragger 2000 is in the cut-off mode, asshown in FIG. 21A, switch 2030 of resonator type current dragger 2000 isin ON state; therefore, the RF is cut off and virtually no RF current ispresent. In the cut-off mode, FIG. 21B shows the antenna radiationpattern corresponding to the current distribution on grounded plane 2021of antenna structure 2020. The main beam of antenna radiation patternfaces the 45° direction, as the arrow indicates.

When resonator type current dragger 2000 is in the guide-in mode, asshown in FIG. 22A, switch 2030 of resonator type current dragger 2000 isin OFF state; therefore, the RF current is guided in following thedirection indicated by the arrow. In the guide-in mode, FIG. 22B showsthe antenna radiation pattern corresponding to the current distributionon grounded plane 2021 of antenna structure 2020. The main beam ofantenna radiation pattern faces the −155° direction, as the arrowindicates.

The above simulation result shows that the antenna radiation patternsobtained by using a resonator type current dragger are the same as theradiation patterns obtained by using pseudo antenna type currentdragger. This is because the resonator can only drag in the RF current,but not radiate. Therefore, it proves that the antenna structure of thedisclosed exemplary embodiments may reconfigure, by enabling ordisabling the current dragger, the guide-in or cut-off of the RF currentof the grounded plane to or from the current dragger to change the RFcurrent distribution of the antenna grounded plane, instead of usingelectromagnetic coupling effect to change the antenna RF currentdistribution on the grounded plane. In comparison with the cell phonewithout the current dragger, the simulation result of average SAR valueshows that the present invention can reduce the impact ofelectromagnetic wave on human.

The following describes the design flow of the antenna structure of thedisclosed exemplary embodiments. FIG. 23 shows an exemplary flowchart ofthe method for manufacturing the antenna structure with reconfigurableradiation patterns, consistent with certain disclosed embodiments.Referring to FIG. 23, in step 2310, at least an active antenna isdistributed on or near a grounded plane and electrically connected to anRF signal source. In step 2320, at least a current dragger iselectrically connected to the grounded plane and configured the guide-inor cut-off mode of the current dragger in the antenna operatingfrequency band and corresponding current path. Step 2330 is to ensureevery current dragger to guide in or cut off the RF current on thegrounded plane to or from the current dragger when in the guide-in orcut-off mode. Then, the at least a current draggers are distributed onor near the grounded plane, as shown in step 2340. Step 2350 is toconfigure, in the antenna operating frequency band, the RF current to beguided into or cut off from the at least a current dragger by enablingor disabling the at least a current dragger.

As aforementioned, the configuration of guide-in/cut-off mode determineswhether the current dragger resonates in the antenna operating frequencyband. The current dragger may be realized with pseudo antenna type,resonator type or monopole type current dragger. The locations and thenumbers of current draggers and the active antennas may also be changedto match the actual application demands of multiple radiationcharacteristics.

In actual application, for example, an active antenna may be designedfollowing the specification and simulations may be performed tounderstand how the current of the active antenna distributes in thefrequency operating band. According to the actual requirement, thecurrent dragger may be pseudo antenna type, resonator type, monopoletype or hybrid type. The configuration mechanism and current path of thecurrent draggers in the resonance/non-resonance modes in the operatingfrequency band. The configuration mechanism may be switch element oradjustable load.

In step 2330, the actual application, for example, may simulate thefrequency response of each current dragger in resonant/non-resonantmodes to check whether the RF current on the grounded plane may beeffectively guided into or cut off from the current dragger to ensurethat each current dragger can effectively guide in or cut off the RFcurrent on the grounded plane to or from the current dragger in theguide-in or cut-off modes.

In step 2350, for example, a controller may be used to enable or disablethe current draggers to configure the guiding in or cutting off the RFcurrent on the grounded plane to or from the current dragger. In theguide-in mode, the RF current may be guided into the current dragger bycoupling or direct flowing.

In summary, the disclosed exemplary embodiments may provide an antennastructure with reconfigurable pattern and manufacture method thereof.The antenna structure uses a controller to enable or disable switches oradjustable load to configure a current dragger in operating frequencyband so that the RF current on the grounded plane may be guided into orcut off from the current dragger. In this manner, the antenna structuremay show different current distributions. The changed RF currentdistribution on grounded plane may also affect the antenna far-fieldpattern (directivity) and near-field electromagnetic energydistribution. The current dragger may be realized with variousstructures, such as pseudo antenna type, resonator type or monopoletype. The direction change of main beam may be achieved up to near 180°.The disclosed exemplary embodiments are also applicable to the antennastructure with low profile.

Although the disclosed has been described with reference to theexemplary embodiments, it will be understood that the invention is notlimited to the details described thereof. Various substitutions andmodifications have been suggested in the foregoing description, andothers will occur to those of ordinary skill in the art. Therefore, allsuch substitutions and modifications are intended to be embraced withinthe scope of the invention as defined in the appended claims.

1. An antenna structure with reconfigurable radiation pattern,comprising: a grounded plane; at least an active antenna, distributed onor near said grounded plane and electrically connected to an RF signalsource; at least a current dragger, distributed on or near said groundedplane and electrically connected to said grounded plane; and acontroller that configures to guide in or cut off RF current on saidgrounded plane to or from said at least a current dragger by enabling ordisabling said at least a current dragger in an antenna operatingfrequency band, to form a plurality of radiation patterns.
 2. Theantenna structure as claimed in claim 1, wherein each of said at least acurrent dragger comprises at least a switch element.
 3. The antennastructure as claimed in claim 1, wherein each of said at least a currentdragger comprises at least an adjustable load.
 4. The antenna structureas claimed in claim 1, wherein each of said at least a current draggeris selected from a group of current draggers with pseudo antenna type,resonator type and monopole type.
 5. The antenna structure as claimed inclaim 4, wherein said resonator type current dragger is a multi-portresonator.
 6. The antenna structure as claimed in claim 5, wherein aconnection structure of output terminal of said multi-port resonator isselected from a group of connection structures with open, short,connecting to a switch element then grounded, connecting to anotherresonator, and connecting to a switch element and then connecting toanother load.
 7. The antenna structure as claimed in claim 4, whereinsaid switch element of said pseudo antenna type current dragger islocated between a pseudo type antenna and an extension part of saidpseudo type antenna.
 8. The antenna structure as claimed in claim 4,wherein said switch element of said pseudo antenna type current draggeris located between a pseudo type antenna and said grounded plane.
 9. Theantenna structure as claimed in claim 4, wherein said switch element ofsaid pseudo antenna type current dragger is located inside a pseudo typeantenna.
 10. The antenna structure as claimed in claim 1, wherein saidcontroller is electrically connected to each of said at least a currentdragger.
 11. The antenna structure as claimed in claim 1, wherein saidcontroller checks whether said current dragger resonates in said antennaoperating frequency band to enable or disable said at least a currentdragger while in said antenna operating frequency band.
 12. The antennastructure as claimed in claim 1, wherein said at least a current draggeris not restricted to be co-planar with said active antenna.
 13. Theantenna structure as claimed in claim 1, wherein said at least a currentdragger is not restricted to be co-planar with said grounded plane. 14.A method for manufacturing antenna structure with reconfigurableradiation patterns, said method comprising: distributing at least anactive antenna on or near a grounded plane, and electrically connectingsaid active antenna to an RF signal source; electrically connecting atleast a current dragger to said grounded plane, and configuring aguide-in or cut-off mode of said current dragger within an antennaoperating frequency band and a corresponding current path; ensuring eachof said at least a current dragger effectively guiding in or cutting offRF current on said grounded plane to or from said current dragger whilesaid current dragger in guide-in/cut-off mode; distributing said currentdragger on or near said grounded plane; and within said antennaoperating frequency band, enabling or disabling said at least a currentdragger to reconfigure said RF current on said grounded plane guidedinto or cut off from said at least a current dragger.
 15. The method asclaimed in claim 14, said method configures said guide-in or cut-offmode depending on whether said at least a current dragger resonates insaid antenna operating frequency band.
 16. The method as claimed inclaim 14, wherein each of said at least a current dragger is selectedfrom a group of current draggers with pseudo antenna type, resonatortype and monopole type.
 17. The method as claimed in claim 14, saidmethod further includes: simulating frequency response of each of saidat least a current dragger in guide-in/cut-off mode to ensure each ofsaid at least a current dragger effectively guiding in or cutting off RFcurrent on said grounded plane to or from said at least a currentdragger while said current dragger in said guide-in/cut-off mode. 18.The method as claimed in claim 14, wherein, in guide-in mode, RF currenton said grounded plane is guided into said at least a current dragger bycoupling or direct flowing.
 19. The method as claimed in claim 14, saidmethod enables or disables said at least a current dragger by acontroller to configure whether RF current on said grounded plane guidedinto or cut off from said at least a current dragger within said antennaoperating frequency band.
 20. The method as claimed in claim 14, saidmethod further includes: adjusting locations of said current dragger andsaid active antenna to meet actual application requirements of pluralradiation characteristics.
 21. The method as claimed in claim 14, saidmethod further includes: adjusting the number of said at least a currentdragger and said active antenna to meet actual application requirementsof plural radiation characteristics.
 22. The method as claimed in claim14, said method further includes: simulating current distribution onsaid grounded plane when said at least an active antenna being withinsaid antenna operating frequency band.
 23. The method as claimed inclaim 19, wherein each of said at least a current dragger has at least aswitch element for configuring to guide in or cut off RF current on saidgrounded plane to or from said current dragger.
 24. The method asclaimed in claim 19, wherein each of said at least a current dragger hasat least an adjustable load for configuring to guide in or cut off RFcurrent on said grounded plane to or from said current dragger.